1. Field of Invention
This invention relates to coupling systems for transferring materials from one flow conduit to another. More particularly, the invention relates to a hub/safety needle cannula designed for use in combination with medicament-containing cartridge units. Preferably, the hub/safety needle cannula and cartridge unit is used in conjunction with a cartridge holder for purpose of safety and easy handling.
2. Reported Developments
Disposable medicament-containing cartridge-needle units for use in conjunction with reusable hypodermic syringe holders are well known in the art. Such cartridges conventionally feature a cylindrical body closed at the proximal end with a flexible piston slideable within the bore of the cartridge and closed at the distal necked-down end with a diaphragm secured to the cartridge by a crimped-on metal collar. The distal necked-down end conventionally is fitted with a steel needle/needle hub unit and a needle sheath. Such needle/needle hub units have, minimally, a sharp end, typical of the type associated with hypodermic syringes.
Such cartridge-needle units can be used in conjunction with reusable syringe holders which allow the user to avoid handling the cartridge-needle unit when the needle is exposed. Nevertheless, health care workers are especially susceptible to accidental and potentially infectious, and indeed, on occasion, possibly fatal, needle strikes due to the careless handling and/or disposing of the cartridge-needle unit after use. The consequences to health care workers of strikes from needles contaminated with various infectious diseases, such as hepatitis or AIDS, can be particularly severe. The frequency of such accidental needle strikes in the United States is surprisingly great, and has been estimated to be approximately one million needle strikes per year. Moreover, the cost to health care organizations for the testing of health care workers accidentally stricken by used needles is a significant burden on health care costs. Therefore, it would be desirable to further protect health care workers by providing medicament containing cartridges without having to expose the user to the needle commonly associated with such cartridges.
In response to the need of preventing "accidental needle strike injuries", numerous devices have been developed which shield or cover the sharp needle tip. One recently developed system, as described in PCT/US89/00273, comprises a blunt cannula which is to be received by a pre-slit injection site. Commercially available under the InterLink trademark, this pre-slit injection site and blunt cannula have been adapted for intravenous administration as described in published patent applications and patents. One of the key features of this system is the elimination of traditional "sharp" needles which are used in various procedures. For example, as described in PCT/US90/01350, the blunt cannula is depicted in a press-fit combination with a syringe of known construction. Rather than using a traditional needle, the blunt cannula is attached to the syringe and then inserted through the pre-slit injection site located in an IV tubing line. The content of the syringe is then delivered into the IV line. Once the content is delivered, the cannula is withdrawn from the site and properly disposed. Hence, the administration of the syringe content, through an IV line, can now be completed without the use of standard needles that can cause accidental needle strikes.
Further, in response to the need of preventing accidental needle strike injuries the prior art has provided a conventional disposable medicament cartridge designed to receive a blunt cannula and which is usable with pre-slit injection sites. More specifically, the coupling system for transferring fluid medicament from a cartridge to a pre-slit injection site comprises:
a fluid flow channel; PA1 a blunt cannula forming the distal end of the fluid flow channel to be received by the pre-slit injection site; PA1 a needle cannula forming the proximal end of the fluid flow channel; and PA1 means for connecting the needle cannula to the blunt cannula. PA1 a hub having a flow channel located centrally therein, said flow channel comprising: a needle cannula having a sharp end at its proximal end; and a blunt cannula at the distal end of the hub; PA1 a first sleeve located on the proximal end of the hub and designed to engage a closure on a medicament-containing cartridge; PA1 a second sleeve located on the distal end of the hub having internal threads thereon to engage a threaded receiving means on an injection site; PA1 a middle portion integral with and connecting the sleeves on the proximal and distal ends of the hub; PA1 a cartridge, comprising a hollow body prefilled with a medication having a sealed diaphragm on the distal end thereof and a piston axially and reciprocally slideable through the interior of said body; and PA1 a coupling system for transferring fluids from said cartridge to an injection site, said coupling system comprising: PA1 a hub having a flow channel located centrally therein, said flow channel comprising: a needle cannula having a sharp end at its proximal end; and a blunt cannula at the distal end of the hub; PA1 a fast sleeve located on the proximal end of the hub and designed to engage a closure on a medicament-containing cartridge; PA1 a second sleeve located on the distal end of the hub having internal threads thereon to engage a threaded receiving means on an injection site; PA1 a middle portion integral with and connecting the sleeves on the proximal and distal ends of the hub and geometrically compatible with a holder assembly; PA1 a syringe holder comprising a frame, a clamp and a plunger element containing a piston stem; PA1 a cartridge loaded into the frame of said syringe holder, said cartridge comprising a hollow body filled with a medication, a sealed diaphragm on the distal end thereof and a piston axially and reciprocally slideable through the interior of said body; and PA1 a coupling system for transferring fluids from said cartridge to an injection site, said coupling system comprising: PA1 a hub having a flow channel located centrally therein, said flow channel comprising a needle cannula having a sharp end at its proximal end; and a blunt cannula at the distal end of the hub; PA1 a first sleeve located on the proximal end of the hub and designed to engage a closure on a medicament-containing cartridge; PA1 a second sleeve located on the distal end of the hub having internal threads thereon to engage a threaded receiving means on an injection site; PA1 a middle portion integral with and connecting the sleeves on the proximal and distal ends of the hub;
The means for connecting the needle cannula to the blunt cannula comprises a hub having a sleeve which extends around and beyond the proximal end of the needle cannula so as to prevent accidental needle strike when the coupling system is snapped onto the fluid medicament-containing cartridge.
While this coupling system prevents accidental needle strike injuries to the health care practitioner, and as a result, greatly advances the an of delivering fluid medicaments to patients, there is still a need for improving the coupling system in relation to its use with the pre-slit sites. The connection between the pre-slit site and the coupling system should provide for a leak-proof seal, easy alignment in repeated use, sufficient holding force to prevent fall-out and proper reseal of the septum in the pre-slit site to prevent entering of airborne foreign matter into the site.
It is an object of the present invention to provide a coupling system for fluid medicaments containing cartridges from which such fluid medicaments can be delivered to an injection site without accidental needle strike to the health care professional or the patients.
It is another object of the present invention to provide a coupling system used in conjunction with a pre-slit injection site that greatly reduces or eliminates leakage, misalignment and the entering of foreign matter into the injection site.
It is still another object of the present invention to provide a more positive means of engaging and locking of the (luer) coupling system to reduce inadvertent disassembling of the cartridge from the injection site.
It is still another object of the present invention to provide a coupling system with a fluid medicament containing cartridge unit which can be used in conjunction with a cartridge holder for purpose of safety and ease of handling.